Method of stunting plant growth with substituted hydrazonium salts



United States Patent Int. Cl. Allln /00 US. Cl. 71-76 6 Claims ABSTRACT OF THE DISCLOSURE Method of stunting plant growth by treating the plant or the soil in which the plant is growing with a compound of the formula in which R, R R and R represent hydrogen, methyl or ethyl, Z denotes an aliphatic or haloaliphatic radical of 1 to 4 carbon atoms and X is a non-phytotoxic anion in an amount sufficient to cause stunting without withering or substantially damaging the blossom or fruit of the plant.

This application is a continuation-in-part of application Ser. No. 513,536, filed on Dec. 13, 1965.

This invention relates to a method for regulating the growth of crop plants with hydrazine derivatives without their withering.

In particular the invention relates to a method for reducing the growth height of cereal plants so that they do not lodge prior to reaping. Moreover, the method according to this invention is suitable for reducing the growth height of ornamental plants, particularly flowers, and especially flowers which grow in a place where there is not sufficient light.

It is an object of the invention to provide a method of regulating plant growth, particularly for inhibiting growth height, without damaging the blossom or fruit of these plants.

It is known that chlorocholine chloride (CCC) may be used for regulating plant growth. Its action is not wholly satisfactory.

We have now found that compounds having the formula R R2 93 [MI-Z] X t. It.

in which R, R R and R may be identical or different and may denote hydrogen or the methyl or ethylradical and Z denotes an alkyl radical having one to four carbon atoms which may bear chlorine, bromine, lower carboxyl groups, lower carboxyalkyl groups, lower alkoxy groups or a hydroxyl group as a substituent or an unsaturated aliphatic radical with two to four carbon atoms which may bear halogen, especially chlorine, as substituent and X denotes the anion of an inorganic or organic acid, cause a reduction in the height growth of many plants, particularly cereals, such as wheat, rye, barley and oats, and also of dicotyledons (for example sunflowers and tomatoes) and various ornamental plants, such as poinsettias and chrysanthemums.

3,497,343 Patented Feb. 24, 1970 The treated plants accordingly exhibit a compact habit; moreover a darker color of the leaves is to be observed.

The action of the compounds is attributable to the cation so that any anion may be chosen. Anionic phytotoxic acids should not be used however if it is desired only to regulate plant growth and not to destroy the plants. Examples of suitable acids are: hydrochloric acid, hydrobromic acid, sulfuric acid, carbonic acid, nitric acid, phosphoric acid, acetic acid, propionic acid, benzoic acid, monomethyl sulfate, monoethyl sulfate, Z-ethylhexanoic acid, acrylic acid, maleic acid, succinic acid, adipic acid, formic acid, chloroacetic acid, p-toluene sulfonic acid and benzenesulfonic acid.

The compounds may be supplied to the plants either through the soil or, by spraying, via the leaves.

They may also advantageously be used mixed with conventional fertilizers and plant protection agents and other carriers. Wetting agents may be incorporated to increase effectiveness. In addition to treatment of the soil and leaves, the seeds may be soaked. Owing to the relatively high plant compatibility, the rate of application may vary widely, for example up to 15 kg. of active substance per hectare. Amounts of 0.5 to 5 kg. per hectare are however usually regarded as adequate.

Production of the new compounds may be carried out by various methods. In general the starting material is a hydrazine which has already been partly or completely alkylated, and this is reacted with a large excess of an alkyl halide; in the case of partly alkylated hydrazines, the new substituted or unsubstituted alkyl radical therefore in general becomes attached to the nitrogen atom bearing most alkyl groups, for example Another possibility is adding on alkylene oxides to hydrazines or alkylhydrazines, for example:

O l+ soon HCl The haloalkyl hydrazonium salts may in turn be used for the production of other types of substituted hydrazonium salts, for example by eliminating hydrogen halide or by nucleophilic aliphatic substitution.

Many of the quaternary hydrazonium salts are strongly hygroscopic.

The production of one of the compounds according to this invention will now be described by way of example:

90 parts by weight of N,N-dimethylhydrazine is dripped at to C. with good stirring into an excess (1,300 parts by weight) of 1,2-dichloroethane. The reaction is exothermic. The whole is allowed to react further for one to two hours and the crystalline product is suction filtered. N,N-dimethyl-(,3-chloroethyl) hydrazonium chloride is obtained which has a melting point of 116 to 1 117 C. after is has been recrystallized from a mixture of alcohol and ethyl acetate. Excess 1,2-dichloroethane may be used again for another reaction after it has been separated from the hydrazonium chloride.

The other compounds may be prepared in an analogous way. The following compounds having the formula in which R, R R R Z and X have the meanings inactive substances. The following abbreviations are used:

weeks after the treatment are shown in the following tables:

M=methyl; E=ethyl; P =propargyl; p-BE={3-brorno- S Height Ofplants o1 ethyl, MA methallyl, B-CE- fi-chloroethyl, A-allyl, 5 Treatment In em. Relative 6 CB=6 chlorobutyl; [3-MCM=fi-methylenecarboxy- U t t d 20 6 methyl; IP=1sopropyl; ,8 ME=,8 rnethoxyethyl; g g i 83 CM=chloromethyl; 2-CA=2-chloroallyl. The final col- CO0 12 kgJha- 15.3 74 umn gives the melting point in C. i213 $3 TABLE R R2 R3 Z X Height of plants H H M M P Chloride 127-129 Sp y H H M M 133434 Treatment In em. Relative H H M M 107-108 H H M M 116 117 15 Untreated 20.6 100 M M H H ca. 130433 000 6 e/ 2 84 H H E E 20. 25 CCO 9 kgJlia 17. 6 85 H H M M 2 -2 7 CMH 6 kg./ha 16. 7 81 H H M M 52 53 CMH 9 kg./ha 16. 7 81 a e a a H H M M 246-545 EXAMPLE 5 H H M M 39-90 20 H H M M CM Ch1oride 116-117 Comparison of the activity of various active sub- 5 E Q 333 33:- 2;? stances is carried out in a vegetation test in Mitscherlich vessels The soil used is a loamy sand having a pH value The following examples illustrate the effect of N-chloof elumatable fractlon 191%; capaclty methYLNNdimethylhydrazonium chloride (CMH) on value) 7.6 6 mval./100 g. of soil. Fertllizmg: 1 g. of N various plants, compared with the effect of chlorocholine as ammomum filtrate chloride (CCC). 1 g. of P 0 as secondary potassium phosphate EXAMPLE 1 1.33 g. of K 0 as secondary potassium phosphate Rye plants are planted in a loamy sandy soil in glass Test P nts: spring wheat. Vessels having f diameter of With pp p 31 grains of wheat are sown in the prepared vessels dosage of nutrlent- At a growth heleht Ofabout 7 m. (later to be thinned out to fourteen plants). Immediately the plants are sprayed with an aqueous solution e qulvalent ft i th substances to be tested are applied f 6 E hectare of actlve SubStahPe- The dlffefences at the rate of 9.42 mg. per Mitscherlich vessel, equivalent 111 i116 helght growth of the PIants S1X Weeks after the 35 to 3 kg. per hectare. During the test period, supply of treatment y bfi Seen from the figures glven belOWI water is kept at 60% of the maximum water capacity of the soil. Height Ofplents Measurement of the length of the haulm, carried out Treatment In em Relative on the mature plants, gives the following values for the Untreated 17 2 100 individual compounds: 000 e kg. /ha 1714 102 CMH 6 kg/ha 14. 5 84 Length of haulm EXAMPLE 2 Compound used Absolute Realtive r Control (untreated) 90. 8 100 Oats plants are planted under the same conditions as in Example 1. The active substances to be tested are intro- N,N-dimethyl-N-(B-brornoethyD-hydrazonium duced into the soil as an aqueous solution on the day on Pg ggfiggfii ijfi g ig,if g;d ii ififfiiifiiid:I: Q13 gig whlch the plants are sown. Six weeks later, the following NiJN-diriethyl-N-isopropylhydrazonium 72 3 79 6 Tom] 6 action can be established:

Summer barley is treated under the same conditions as in Example 2 with 12 kg./ha. of CMH and the same amount of CCC in the form of aqueous solutions. The efiect of the agents used after 6.5 Weeks may be seen below:

Height of plants Treatment In em. Relative Untreated 31.1 100 C O C 27. 8 89 CMH. 27. 5 82 EXAMPLE 4 Wheat plants are sown under the same conditions as in Example 1. Treatment is carried out both via the soil on the day of sowing and as a leaf spray on the plants which are about 7 cm. in height. The results 7.5 and 6.5

As may 'be seen from the above results, the hydrazonium derivatives tested in this experiment exhibit an action which is clearly superior to that of CCC.

In further tests it has also been established that N,N- dimethyl-N-isopropylhydrazonium chloride, N,N-dimethyl-N-(fi-methylallyl)-hydrazonium chloride, N,N-dimethyl-N-propargylhydrazonium chloride and N,N-dimethyl- N-ethylhydra-zonium bromide are biologically active in the same way as the above-mentioned hydrazine derivatives.

We claim:

1. A method of stunting plant growth which comprises applying to said plant or to the soil in which the plant grows a compound of the formula wherein R, R R and R each represent a substituent selected from the group consisting of hydrogen, methyl and ethyl, Z represents a substituent selected from the group consisting of an alkyl or alkenyl radical of 1 t0 4 carbon atoms and the bromoand chloro-substituted alkyl or alkenyl radicals of 1 to 4 carbon atoms and X represents the anion of a non-phytotoxic organic or in- 5 organic acid, said compound being applied in an amount sufficient to stunt the growth of the plant without withering or substantially damaging the blossom or fruit of the plant.

2. A method as claimed in claim 1 wherein said compound is applied in an amount of about 0.5 to 15 kg. per hectare.

3. A method as claimed in claim 1 wherein said compound is N-chloroethyl-N,N-dimethylhydrazonium chloride.

4. A method as claimed in claim 1 wherein said compound is N,N-dimethyl-N-(B-bromoethyl)-hydrazonium bromide.

5. A method as claimed in claim 1 wherein said compound is -N,N-dimethyl-N-allylhydrazonium chloride.

6. A method as claimed in claim 1 wherein said compound is N,N-dimethyl N isopropyl-hydrazonium bromide.

References Cited UNITED STATES PATENTS 2,885,399 5/1959 Omietanski 260-583 2,901,886 9/ 1959 Doerner 260-583 2,955,108 10/ 1960 Omietanski et a1 260-205 3,083,229 3/ 1963 Oja 260-583 6 3,098,017 7/1963 Walter et al. 260-583 3,156,554 11/1964 Tolb'ert 71-76 3,156,555 11/1964 Tolbert 71-76 3,188,363 6/1965 Amidon et a1. 260-863 5 3,197,504 7/1965 Harvey 71-121 3,240,799 3/ 1966 Hag eman et a1 71-76 3,395,009 7/1968 Oettel 71-76 FOREIGN PATENTS 10 1,461,144 10/1966 France.

OTHER REFERENCES Omietanski et al.: Reaction of Chloramide etc. (1956), CA 50, pp. 13024-25 (1956).

Westphal: Invert Soaps (1941), CA 35, pp. 6958-59 5 1941).

0 LEWIS GOTTS, Primary Examiner G. HOLLRAH, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION Patent No. 5,497,343 Dated February 2 1970 Inventor(s) Johann Jung 613 6.1

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 62, "is" should read --it---.

SIGNED AND SEALED JUL 141970 Anest:

Edward M. Fletcher, Ir.

Attesting Officer WILLIAM E. SW, IR. Oomissioner of Patents 

